Measuring method of tilt angle of liquid crystal element

Abstract

Abstract PURPOSE:To measure the tilt angle of a liquid crystal element, by measuring the initial electrostatic capacity of the liquid crystal element under the state a magnetic field is not applied, measuring the changing characteristic of the electrostatic capacity with the magnetic fields being applied, obtaining the lowest value, and performing specified computation. CONSTITUTION:Transparent electrodes 6 and 8 are evaporated on the inner surface of transparent glass substrate 2 and 4. Oriented films 12 and 14 are provided on the electrodes. Liquid crystal molecules 10 are provided between the films. Initial electrostatic capacity C(theta) is measured under the state a magnetic field is not applied to the liquid crystal. Then, with the magnetic fields H1-H4 being applied, the changing characteristic of the electrostatic capacity is measured, and the lowest value Cmin. of the electrostatic capacity is obtained. By using permittivity epsilon11 in the direction parallel to the molecule axis of the liquid crystal 10 and permittivity epsilon(-) in the direction perpendicular to the axis, a tilt angle theta is obtained by the following expressions: a) for p type (epsilon11>epsilon(-)), theta=sin<-1>{(C(theta)/ Cmin.-1)epsilon(-)/(epsilon11-epsilon(-))}<1/2>; b) for n type (epsilon(-)>epsilon11), theta=cos<-1>{(C(theta)/ Cmin.-1)epsilon11/ (epsilon(-)-epsilon11)}<1/2>.

Inventors

• 👤 Makoto Sato
• 👤 良 佐藤
• 👤 Norio Yamamoto
• 👤 典生 山本

Bibliographic Details